In spite of the significant improvements made in the oral health during the past two decades, the decline in dental caries has not been uniform across all populations. In Puerto Rico, dental caries has been identified as an important health problem. specially in low socioeconomic groups. Among infants and toddlers, infant caries, commonly called Baby Bottle Tooth Decay (BBTD) continues to be a constant problem without adequate resolution. The goals of this study are (1) to test chemotherapeutic interventions to prevent BBTD among disadvantage Puerto Rican children, aged 12-18 months, from Mother Infant Care Program (MIC) from the Region Metropolitana de Salud in Puerto Rico, and (2) to assess microbiological and behavioral risk factors. The specific interventions to be tested in this study are the professional application of a 50 mg/ml sodium fluoride varnish and a 10% povidone-iodine solution. To assess risk, subjects will be interviewed concerning feeding practices hygiene, social support, parental stress and self control and demographic variables, and microbiological samples will be collected. The pilot study will recruit 125 infants who engage in a high risk feeding behavior, i.e., sleeping with a bottle that contains a cariogenic substance; and harbor> 1% mutans streptococci in a pooled plaque sample obtained from their primary maxillary incisors. These infants subjects will be randomized into four groups: sodium fluoride varnish (Duraflor) and a solution containing a 10% povidone-iodine (Betadine); active varnish and a placebo solution; placebo varnish and active solution; and a placebo varnish and placebo solution. Varnish/placebo will be applied at baseline, four, and eight months; the solution/placebo at baseline, two, four, six, eight, and 10 months. Decay (the primary dependent measure) and decalcification will be assessed at baseline, four, eight, and 12 months. On a bimonthly basis (once in two months) the level of mutans streptococci and lactobacilli in a pooled plaque sample obtained from the primary maxillary incisors of each subject will be obtained and levels of flora assessed. To reduce subject attrition culturally sensitive behavioral techniques that facilitate communication and enhance cooperation will be employed.